comb :: (Eq t, Num t) => t -> [a] -> [[a]]
comb n xs = go n xs [] []
 where
  go 0 _ ys zs = reverse ys : zs
  go _ [] _  zs = zs
  go n (x:xs) ys zs = go (n-1) xs (x:ys) (go n xs ys zs)

lcmList :: Integral a => [a] -> a
lcmList [x] = x
lcmList (x1:x2:xs) = lcmList (lcm x1 x2 : xs)

main = do
 [n,l,h] <- map read . words <$> getLine
 cs <- map read . words <$> getLine
 print (onlyOne n l h cs)

onlyOne :: Integral t => t -> t -> t -> [t] -> t
onlyOne n l h cs = sum $ zipWith (*) as (map (sum . map (divs . lcmList)) ccs)
 where
  divs x = div h x - div l x + (if mod l x == 0 then 1 else 0)
  ccs = map (flip comb cs) [1..n]
  as = zipWith ($) (cycle [id,negate]) [1..n]